Effect of Landfill Leachate on the Growth Parameters in Two Selected Varieties of Fiber Hemp

The influence of landfill leachate on selected growth parameters in two varieties (‘Bialobrzeskie’ and ‘Monoica’) of hemp ( Cannabis sativa L.) was studied to evaluate phytoremediation potential of these varieties. The plants were cultivated in hydroponic culture in Knop's nutrient solution. Landfill leachate was added to nutrient solution in concentrations of 10, 15, 20 and 40%, respectively. After 14 days of cultivation, selected parameters of above-ground organs and root system were determined in experimental plants, namely height of plants, dry weight of aerial parts, total leaf area, total length of the root system, dry weight of the root system and the content of photosynthetic pigments in leaves. The leachate application affected all the monitored parameters: the decrease in height of the plants, length of the root system, dry weight, total leaf area, and content of photosynthetic pigments were observed. While the 10% and 15% concentration of leachate often caused only a slight decrease in the monitored parameters, the 20% concentration dramatically affected all the observed characteristics. Concentration of 40% caused severe stunting and in some cases, even dying of experimental plants. The higher degree of tolerance in almost all parameters was observed in ‘Monoica’. This variety appears to be more suitable for landfill leachate treatment, but further research is needed, especially in terms of heavy metals accumulation in individual organs. According to our knowledge, this paper represents the first study on the use of hemp for treatment of landfill leachate.